For example, I render this view:
html
head
body
form(action="/buscar" method="POST")
label(for="nombre") Nombre
input(type="text" name="nombre")
input(type="submit")
block contenido
h1 usuarios
Then in another route this other view is loaded but as only a part of it changes, that is my question whether it is ajax or is it really loading everything
extends ./index.jade
block contenido
for dato in datos
li #{dato.nombre}
You have a confusion of concepts. Jade is a library to write views in order to avoid the repetition of HTML (open and close tags) and force to give more order to the code (through tabulations).
To use it, it is processed at the server level and generates HTML code which is delivered to the client once processed.
Now extends is a Jade construction, through which you can extend a view (which works as a template) to reuse as much code as possible
As an example:
// vista layout.jade
doctype html
html
head
block title
title Default title
body
block content
Here you define two block 's: One for the title ( title , with default value title Default title ) and another for the content ( content ).
Then, when extending from this view:
// vista article.jade
extends ./layout.jade
block title
title Article Title
block content
h1 My Article
you indicate that block title has content title Article Title and% block content content h1 My Article .
Thus, you have a single layout that is common for all possible views of your application / web and only modified in one place.
And finally, no, it's not AJAX, it's processing server-level file article.jade and delivering as HTML to the client.
I recommend reading the documentation
It is loading everything, the extends in jade are very useful to include a content that is repeated on all pages. As for example the header or footer that is always repeated on all pages.